76bd878d959c79ef17ed90cc7d13dffea9327ee2 is the first bad commit
commit 76bd878d959c79ef17ed90cc7d13dffea9327ee2
Author: Ronald S. Bultje <rsbultje@gmail.com>
Date: Sat Nov 30 09:08:54 2013 -0500
vp9: add a 2-pass decoding mode, and add frame-mt support.
For a random 1080p sample, decoding time went from 9.7sec (1 threads)
to 6.0sec (2 threads) and 5.2sec (4 threads) in 2-pass decoding mode.
I don't have any samples that use the parallelmode feature, but the
gains should be higher.